Moving-picture machine.



E. M. WOODEN.

MOVING PICTURE MACHINE.

APPLICATION FILED 213.11, 1914.

3 45 Patented Jan. 5, 1915.

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Inventor:

WM WA {0 62 E. M. WOODEN.

MOVING PICTURE MACHINE.

APPLICATION FILED FEB.11,1914.

Patented J an. 5, 1915.

2 SHEETSSHEET 2.

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51.42.. W. w w

M AtZj PATENT EARLE M. WOODEN, OF NEW YORK, N. Y., ASSIGNOR 0F ONE-HALFT0 ANTHONY B.

' CAVANAGH, OF NEW YORK, N. Y.

MOVING-PICTURE MACHINE.

Application filed February 11, 1914.

1 0 all whom it may concern:

Be it known that I, EARLE M. VVooDnN, a citizen of the United States,and a resident of the borough of Manhattan of the city of New York, inthe State of New York, have invented certain new and usefullinprovemeuts in Moving-Picture Machines, of which the following is aspecification, reference being had to the accompanying drawings, forminga part hereof.

This invention relates to moving picture machines and has for itsprincipal object to provide means whereby the flickering or variation oflight on the screen is minimized.

One practical embodiment of the invention is illustrated in theaccompanying drawings, although it will be evident as this descriptionproceeds that a different disposition of the source of light whereby theflickering eifcct is reduced may be employed and the construction of theshutter may be altered without departing from the spirit of theinvention.

It has formerly been the general practice to provide a shutter adaptedto cut off from the screen the main source of light during the briefinterval while one picture on the film is being moved forward and thenext succeeding picture is being brought into proper position to beprojected upon the screen. The result of this arrangement is, of course,alternate periods of absolute darkness and illumination on the screenand the effect on the eye, the flickering effect above referred to. Tominimize this flickering it is proposed in accordance with the presentinvention to provide a shutter which, while cutting off from the screeneither the entire image of the pictures being changed or a portionthereof, shall at all times permit beams of light, preferably from theprincipal source of light, to "fall on the screen, so that there isnever a period of absolute darkness, the changing degrees ofillumination being within such narrow limits as to be unappreciablc tothe eye. It has been found in practice that When most of the image iscut off the remaining portion does not appear distinctly but leaves onthe screen merely a difiused light of less intensity than would be thecase if the entire projecting beam fell thereon without interference.The theory of the invention depends primarily on the Specification ofLetters Yatent.

Patented Jan. 5, @915.

Serial No. 817,958.

well known physical composition of shadows into the two zones commonlytermed the umbra and the penumbra. In the present invention, the zone oflight remaining on the screen during the time that the image of thepicture or a portion thereof is cut off by the shutter corresponds tothe penumbra of a shadow, while the beam of light interrupted by theshutter at this time leaves on the screen, in theory, the umbra of theshadow. In practice, of course, these zones cannot be distinguished bythe eye, but a reference to them will serve to illustrate the changingdegrees of illumination which are produced on the screen by the use ofthe shutter hereinafter particularly described and the relationshipthereof to the other parts of the machine.

The invention will be described more particularly with reference to theaccompanying drawings, in which Figure 1 is a fragmentary view in sideelevation of so much of a moving picture machine as is necessary for aclear understanding of the invention, showing particularly the positionof the shutter with respect to the projecting lens and the film. Fig. 2is a view in elevation of one form of the improved shutter and showingparticularly its relationship to the projecting lens and the pictures onthe film. Fig. 3 is a diagrammatic view of the paths of certain of therays of light from the main source of light, this main source of lightbeing indicated together with the film, the pro ecting lens, the shutterand the screen.

I or the purposes of this description, it will be asumed that a suitablesource of light is provided in such position that its rays are collectedand pass through a lens located at a which is positioned directly behindand in proper relationship to the film b and its operating mechanism,indicated generally by the train of gears 0 operable by means of thecrank (Z. One of the actuating spools of the film b may carry on one endof its shafta bevel gear a in mesh with a bevel pinion f which iscarried on a shaft 9 extending horizontally along the side of the filmsupporting devices and carrying ad acent its forward end a rotaryshutter h of the form hereinafter described. By the mechanismjust'described it will be understood that the movement of the film isproperly synchronized with respect to the rotary movement of theshutter, the result being that the Shutter is interposed between theimage of the picture or a portion thereof and the screen while onepicture is being moved out of its projecting position and replaced bythe next succeeding picture to be shown, and is moved out of the path ofthe projected image to permit the image to appear on the screen at theinstant the picture on the film is in the proper position to beprojected. As usual, a projecting lens 2' is mounted in line with thecollecting lens at (L and the picture to be shown in such a manner thatthe image of the picture -as it appears on the screen, shall bemagnified and distinct. It is the usual practireto employ a convex orconverging projecting lens, and this invention is described. on theassumption that such a lens is actually employed, will appear from Fig.3. The beam of light, while, of course, controlled by the shutter 71.,is not concentric with the supporting shaft 9 of said shutter, but thesaid shaft is off-set with respect to the lens and extends parallel withthe axis thereof, sothat only a portion of the shutter is effective toclose the lens i, as will appear more particularly hereinafter when thespecific form of the shutter h is pointed out.

In realizing the invention in accordance with the illustrated embodimentit is proposed to take advantage of the main source of light of themachine for the purpose of keeping the screen partially illuminatedduring the time the shutter is in position to out off the image on thescreen, although it will be evident that an independent source of light,properly controlled, will accomplish the desired result. Accordingly, itbecomes possible to employ a single shutter for the purpose of cuttingoffthe image or a portion thereof in the manner described and, at thesame time, permitting the main source of light to shed certain of itsrays on the screen at all times. As shown in Fig. 2, the shutter 71.,while generally of the same outline as the well known three-wingshutter, is formed with a main body portion 71/ and radial ribs 72.extending outwardly therefrom and carrying arcuate segments 7L3concentrically arranged with respect to the supporting shaft g of theshutter. As will be understood this shutter may be stampedfrom a singlepiece of metal. The concentric se ments k are spaced from each otherat'sudh distances as may be found desirable in View of the speed atwhich the film is designed to be operated and the gear ratio between thesupporting shaft 9 of the shutter and the .actuating spools for thefilm. It will be observed further from Fig. 2 that the picturesindicated generally by the shaded portions 6' of the film Z) are of awidth less than the diameter of the rojecting lens i, indicatedgenerally by the roken line in said figure. The width .the screen whenthe shutter whether said portion passes through the pic-.

ured radially, may be equal to or less than the width of the image ofthe pictures Z) on the film Z; at the place where the shutter ispositioned, so that when one of the segments k is in position to cut offthe image of one of said pictures Z) or a portion thereof from thescreen, certain of the rays from the main source of light will bepermitted to pass the said segment ii to fall on the exhibiting screenand keep the same partially illuminated while the next succeedingpicture is being moved into its projecting position and the effect onthe screen will be a diffused light whether the entire image or only aportion thereof is cut olf, that portion which is not cut off not beingdiscernible. For convenience in this description and the claims, theexpression cut off as applied to the image means that either part of theimage is out 01f (as shown in the drawings) or that all of it is cutoff, the effect in either case a being a realization of the invention inthat a diffused light 1s thrown on the screen, while all of the distinctimages, in so far as they can be seen bythe naked eye, are cut off.

In Fig. 3 the theoretical arrangement of the paths'ofcertain of the raysfrom the main source of light with reference to the pictures on thefilm, the lens, the shutter and the screen, is clearly shown. Theprojecting beam, as defined by the dotted lines is, serves to throw theimage of the picture Z) on to the screen, indicated generally by thereference character Z, after the said beam has passed through theprojecting lens 2' and the image of the picture has been inverted in amanner which will be'understood. What might be termed the marginalportion of the projecting beam,--defined by the lines la, 70, serves toilluminate the screen Z theoretically to the extent indicated, although.jthis portion of the beam is difiused and does not throw any distinctimages on is closed ture or on the sides thereof. When the shutter 71,has one of itssegments 7L3 moved into position to cutoff the image ofthe picture 6' to permit the next succeeding picture to be moved intoprojecting position, the screen Z is illuminated solely by the so-calledmarginal portion of the beam of light defined by the lines 72, 7c. Theresult is that the screen is never left in absolute darkness and a merechanging degree of the intensity of the light is necessitated by theinterposition of the shutter 71.; By reason of the comparatively highrate of speed at which the .film travels and the correspondingly highspeed of rotation of the shutter 71., this changing degree ofillumination of the screen is unappreciable to the naked eye and theinjurious flickering commonly present in moving picture exhibitions iseliminated.

While it will be evident that the present invention is not concerneddirectly with the position of the shutter h with respect to theprojecting lens 2', it might be pointed out that, of necessity, theshutter is mounted near the focal point of said lens in order that thesegments in may not cutoff the image of the picture I) at a place wheresaid image is comparatively small. Since the rays of light convergeimmediately after leaving a convex projecting lens, such aplace Will befound inside of the focal point of the projecting lens and at a littledis tance in front of the lens, as indicated generally in Figs. 1 and 8.

As noted before, it will be evident that other forms of shutters may beemployed in practising the present invention and the relative positionsand arrangement of the projecting light, film, lens and shutter altered,Without departing from the spirit of the invention.

I claim as my invention:

1. In a moving picture machine, means to project a beam of light, meansto cut off certain rays of the beam periodically from the screen,certain other rays being interrupted by said second named means andserving to illuminate the screen at all times.

In a moving picture machine, means to project a beam of light, means tocut off certain rays of the beam periodically from the screen, saidsecond named means permitting the free passage of other of said rays toilluminate the screen at all times.

3. In a moving picture machine, means to project a beam of light, ashutter to cut off from the screen periodically the images of thepictures on the film, said shutter permitting the direct passage of raysfrom the source of light past it at such times to keep the screenconstantly illuminated.

4. In a moving picture machine, the combination with the projectinglens,,of a shutter mounted operatively with respect to said lens to cutoff periodically from the screen the images of the pictures on the film,the effective area of the shutter being less than that of the beam oflight and the area of the lens being greater than that of the picturesto be projected, the pictures, lens and shutter being so mounted withrespect to each other as to permit rays of the main source of light topass by the shutter and illuminate the screen at all times.

5. In a moving picture machine, the combination with the projectinglens, of a shutter mounted operatively with respect to said lens andnear the focal point thereof to cut off periodically from the screen theimages of the pictures on the film, the eifective area of the shutterbein less than that of the lens and the area of the lens being greaterthan that of the pictures to be projected, the pictures, lens andshutter being so mounted with respect to each other as to permit rays oflight from the main source of light to pass by the shutter and 11111-minate the screen at all times.

6. In a moving picture machine, the combination with the projectinglens, of a rotatable shutter mounted operatively With respect thereto,and means to connect operatlvely the shutter and the film operatingmechanism to synchronize their movements, said shutter comprising aplurality of independent segments movable successively across the axisof the lens to cut off the images of the pictures from the screen, saidsegments being radially of a Width less than the diameter of the beam oflight, whereby rays from the source of light may pass at the sidethereof and illuminate the screen at all times.

This specification signed and witnessed this ninth day of February, A.D. 191.4.

EARLE M. WOODEN.

